1. Field of the Invention
The present invention relates to a block synchronization detection apparatus and method, and, more particularly, to a block synchronization detection apparatus and method for detecting a block synchronization by which an error correction code (ECC) block is discriminated from another ECC block in a system having a decoder for decoding an ECC in units of ECC blocks, each block including a plurality of sectors.
2. Description of the Related Art
Systems having a decoder for decoding an ECC in units of ECC blocks, where each block includes a plurality of sectors, include drivers for driving a disc, such as a DVD-ROM, a DVD-R, a DVD-RW, a DVD+R, a DVD+RW, a DVD-RAM, or a blu-ray disc (BD). Each sector contained in an ECC block is allocated a number so that the sectors can be discriminated from one another. For example, when one ECC block contains 16 sectors and the sector number is sequentially increased from 0, the sectors are numbered as 0, 1, 2, 3, . . . , 14, and 15.
Thus, a decoder of a conventional disc driver performs block synchronization using sector numbers. That is, the conventional decoder detects a sector number of input data and generates a block synchronization detection signal if the detected sector number is a first sector of an ECC block. When one ECC block contains 16 sectors and the sector numbers are sequentially increased from 0, a sector number indicating the first sector of the ECC block is represented as 0 (0000 in the binary number system), and when the sector numbers are sequentially decreased from 15, the sector number indicating the first sector of the ECC block is represented as 15 (1111 in the binary number system).
However, if due to defects of the input data or other reasons, the first sector number of the ECC block is not detected, the conventional decoder cannot detect block synchronization for the currently-input ECC block. For example, when one ECC block contains 16 sectors and a sector number is sequentially increased from 0, if an (n−1)-th sector number is 15 and an n-th sector number is 1, the conventional decoder cannot detect block synchronization.
Block synchronization is used to control a buffer memory for storing data in units of input ECC blocks or to correct data errors. However, if block synchronization of an m-th ECC block cannot be detected, the buffer memory is overwritten with data of the currently input m-th ECC block in a region in which an (m−1)-th ECC block is stored. Thus, errors occur in the number of reproduced ECC blocks such that normal data processing cannot be performed.
In addition, if block synchronization for the m-th ECC block cannot be detected, error correction for the (m−1)-th ECC block is not performed. This is because if block synchronization for the m-th ECC block is detected, error correction for the (m−1)-th ECC block is performed.